TUCSON, Ariz. — Randy Loughner was always reclusive. But since his son's alleged shooting rampage last month, the father has shut himself behind what one neighbor calls "an elaborate cage."

In recent weeks, Loughner has built a substantial wooden enclosure, more than 6 feet high, obscuring his front door and windows. The four horizontal windows on the garage door have been papered over, the diamond-shaped openings atop the block wall to his back yard closed off with little plywood plugs.

Even the white mailbox out front has been replaced by a heavy black steel one with a locked drawer.

"He was already secluded, so he was already set up for it, and used to it," says Stephen Woods, who lives in the house to the left of Amy and Randy Loughners'. "So I imagine it's not bothering him much. I don't think his life has changed that much."

But life has undoubtedly changed.

Until Jan. 8, the couple's 22-year-old son, Jared, shared the modest beige block and brick home where the couple have lived for nearly three decades. Now, he sits in a cell, facing federal charges of attempting to assassinate U.S. Rep. Gabrielle Giffords and two of her aides. Six people, including a federal judge, were killed and 13 injured in the shooting during a Giffords meet-and-greet outside a Tucson grocery store, and more charges are expected.

Except for a brief written statement, the Loughners have kept their silence. They have not returned messages left by The Associated Press, and relatives have also refused to talk.

Some thought the couple had moved away from the 1,400-square-foot home where they raised their only child. But then neighbors began hearing the hammers and saws.

'He comes out after dark'
Ron Johnson has seen the husband coming and going in his El Camino, one of several vintage cars he owns.

"He comes out after dark," says Johnson, who lives in the house directly across from the Loughners but who hasn't even tried to speak with them in ages. "He comes out of that garage, closes it and scoots down that highway."

Johnson says he tried to be friendly with the family. He would see Randy Loughner — who was once in construction but now appears not to work — watering his plants or sweeping the driveway and would try to strike up a conversation.

Philip Seymour Hoffman withdrew a total of $1,200 from an ATM at a supermarket near his New York City apartment the night before he was found lifeless in his bathroom with a syringe still in his left arm, sources told NBC News.

"On the other hand, he's probably the best neighbor I ever had," he says with a chuckle. "He doesn't talk to you and doesn't borrow" stuff.

George Gayan, 82, has lived on the Loughners' right for nearly 30 years. When Jared was 3 or 4, he would come over to play with Gayan's great-grandson. Amy Loughner, who works for the county parks department, would sometimes accompany him.

If Loughner's privacy concerns seemed exaggerated before, they are now very real.

Two days after the shootings, Loughner called the sheriff's office to complain that people were hanging over his back wall trying to take photographs. He told deputies he had caught a reporter in his back yard with a camera, and had chased her away.

No one has been charged.

These days, Woods doesn't even see Loughner out watering his plants or walking the family's little black and white dog. And that's just fine with him.

Woods says his relationship with Loughner was bad from the beginning. He had only been in the house a couple of days, he says, when Loughner began shouting obscenities at him over some garbage that had been left behind by the previous residents.

He says Loughner would glare at him and his family as he drove by in his orange Camaro. When Loughner glowered at him one morning, Woods decided to stare back.

"It must have gone on for two or three minutes," he says, puffing on a cigarette. "He's just sitting there, just glaring at me. And finally he just walked away. And that was it. He never said anything."

Woods' daughter, Stephanie, is the same age as Jared and was in some of his classes at high school. Woods always thought it strange that the neighbor boy who rode his bike past their house would have nothing to do with her.

"There's something off about the kid. And when you think about the kid, Jared, you think about the parents. And you look at the parents and say, 'Yeah, well the dad's really angry," says Woods.

"He has some issues, the father. I think it's trickled down on the son. And it's too bad."